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2013 Challenger SXT
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Discussion Starter #1
Showing thinning of the blades increase air flow. I have half shaft and thinned the shafts on my throttle body in the past only because it seemed to reason it would gain airflow. Nice to see some flow bench work to back that up. whether you think your engine needs more air flow or not, if you can do something for free and know it increases air flow why not do it, no harm no foul, the worst you gain nothing, the best you gain a few ponies, why wouldn't you do it?


http://nopr.niscair.res.in/bitstream/123456789/23129/1/IJEMS 20(5) 350-360.pdf
 

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2013 Challenger SXT
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Discussion Starter #2
One thing I have notice with some of the throttle body that are aftermarket "ported" and calling them 85 mm or 87mm they are just straight cutting them right into a 90 degree wall right below the throttle blade, to me that's so stupid. It would seem to be better to tapper from the edge to the bore. tapper from the back side of the blade to the intake opening.

I looked into the TB's for the 6.4 and those straight cut bore openings are just not right and on top of that they don't even bother to half shaft or cut down the shafts in the middle which is know to increase air flow. To me these company's that are just boring out the centers are really half ass'n it just to take your money.


Looks like I will be hand porting my stock 80 mm and half shaft it and thin the lower shaft as well, at least I know for sure this increases air flow whether my 6.4 needs it or not and it free air flow.

I have been looking and those that have been just tapering stock throttle body's from the edge to the throttle blade and keeping everything smooth with no hard transitions seem to be picking up 30 or more cfm.

One person claimed every 15 cfm is about 1 hp gain. One picked up 140 cfm by porting and doing the throttle shaft trick. this was a before and after bench flow reading on same throttle body.
 

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One thing I have notice with some of the throttle body that are aftermarket "ported" and calling them 85 mm or 87mm they are just straight cutting them right into a 90 degree wall right below the throttle blade, to me that's so stupid. It would seem to be better to tapper from the edge to the bore. tapper from the back side of the blade to the intake opening.

I looked into the TB's for the 6.4 and those straight cut bore openings are just not right and on top of that they don't even bother to half shaft or cut down the shafts in the middle which is know to increase air flow. To me these company's that are just boring out the centers are really half ass'n it just to take your money.


Looks like I will be hand porting my stock 80 mm and half shaft it and thin the lower shaft as well, at least I know for sure this increases air flow whether my 6.4 needs it or not and it free air flow.

I have been looking and those that have been just tapering stock throttle body's from the edge to the throttle blade and keeping everything smooth with no hard transitions seem to be picking up 30 or more cfm.

One person claimed every 15 cfm is about 1 hp gain. One picked up 140 cfm by porting and doing the throttle shaft trick. this was a before and after bench flow reading on same throttle body.
The factory manifold opening is 84mm. This is the primary reason the throttle body centers are bored. Arrington makes a true 84mm unit that is technically the max that would work efficiently with the stock manifold opening.

This is one thing I like about the new Edelbrock manifold, as it supports the OEM 92mm Hellcat throttle body.
 

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One thing I have notice with some of the throttle body that are aftermarket "ported" and calling them 85 mm or 87mm they are just straight cutting them right into a 90 degree wall right below the throttle blade, to me that's so stupid. It would seem to be better to tapper from the edge to the bore. tapper from the back side of the blade to the intake opening.

I looked into the TB's for the 6.4 and those straight cut bore openings are just not right and on top of that they don't even bother to half shaft or cut down the shafts in the middle which is know to increase air flow. To me these company's that are just boring out the centers are really half ass'n it just to take your money.


Looks like I will be hand porting my stock 80 mm and half shaft it and thin the lower shaft as well, at least I know for sure this increases air flow whether my 6.4 needs it or not and it free air flow.

I have been looking and those that have been just tapering stock throttle body's from the edge to the throttle blade and keeping everything smooth with no hard transitions seem to be picking up 30 or more cfm.

One person claimed every 15 cfm is about 1 hp gain. One picked up 1 80 cfm by porting and doing the throttle shaft trick. this was a before and after bench flow reading on same throttle body.
Dan Arcand at The Fastman - Specializing in Mopar Performance Parts tapers his oversized 84mm TBs. There is a marked improvement in throttle response from his modifications.
 

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FWIW there are gains to be made from cleaning up the plastic intake manifold runner seams as well, the kind of gains you are looking for.
Keep up the good work!
 

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This is what I was talking about in the above post, I'm not sure I explained it that well...



 

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The protrusions into the the flow path on my 392 looked and felt significant as BMason suggested. I removed the protrusions using a die grinder with emery cones. Its an easy task if one is proficient with rotary tools. I don't have any data that indicates a performance gain from this mod but it is logical to me that removing protrusions and irregular shapes form the flow path is a good thing. As ddennis stated, it's free and at least in theory increases air flow so why not do it.
 
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